2600 Jr black screen

[kikenovic]

Hey everyone, hope this thread finds you well.

 

Recently I got a 2600 Jr. When I insert Pacman or Combat I get a black screen with a green line on the left and red line on the right. With ET I get a distorted line on top. With Kangaroo (brand new) I get scrolling garbage. With no cartridge sometimes I get a solid black screen, sometimes random colors. The BW switch has no effect and the reset and select buttons don't seem to have any effect either.

 

So far I tried cleaning the slot and the carts with the same results.

 

You advise is highly appreciated.

 

https://goo.gl/I4v4wC (with no cart)

 

https://goo.gl/bWH1HO (Kangaroo)

 

https://goo.gl/WRnLdD (with ET)

 

Thanks.

 

 

[kikenovic]

Just noticed the links to the pictures don't work. Let's see if I'm lucky this time.

 

With ET

 

With Kangaroo

 

With No cart

 

[zylon]

You could try cleaning the cart slot and pins, but that looks like an IC failure.

[Thomas Jentzsch]

Does the sound work?

[kikenovic]

Does the sound work?

With cartridge there is no sound. Without cartridge there is a weird noise.

[kikenovic]

So last night I took it apart and cleaned everything to the best of my knowledge. Same behavior. Checked the voltage regulator, input is about 11v output is 5.15v (not sure if thats acceptable).

 

I read on a reddit post that a healthy console would show random vertical colored bars and make noise when no cartridge is present. So I'm thinking something is wrong with the cart slot. Next step will be redoing the solder in the cart port.

[Osgeld]

There's only 3 major parts of a 2600 seems that your tia chip is doing something that leaves the riot and CPU

 

The riot cann be found on jameco as new old stock or old the cpu is fairly easy to find on eBay

 

But on a jr they are soldered in so it's not just yanking one and trying a new one

[+Stephen Moss]

While the input to the regulator seems a little higher that I would expect that may be due to the fact the system is not operating correctly the regulator can cope with that and its output voltage is acceptable.

 

If all the ICs are socketed and you have spares the simplest solution is to swap each of them (one a at time) and see which (if any) of them return the system to an operational state thereby identifying the faulty device. If that is either not an option or does not restore the unit to an operational condition then the first things I would check are...

 

6507: Pins 1 & 4 = High, Pin 2 = Low

TIA: Pins 20 & 23 = High, Pins 1 & 22 = Low, Pin 11 - report voltage reading

6532: Pins 20 & 34 = High, Pin 1 = Low

 

Where Low is 0 - 0.4V and High is 2.7 - 5V although in most case they will be within 0.2V of the supply voltages.

If you do not know which pins are which on the top of the ICs there should be a circular indentation in one corner and/or a semicircular cut out in the center of one end. The end pin located to the left of those is pin 1 and pins are numbered sequentially in an anticlockwise direction (down the left side then up the right side)

[kikenovic]

Thanks Osgeld and Stephen for your suggestions. By just touching I suspect the 6532 is the culprit (almost immediately gets super hot). I have a working system on the way, I'll use its chips for testing.